Influence of pedoclimatic conditions and orchard management on fruit quality characteristics in hazelnut cultivars 'Tonda Gentile Romana' and 'Tonda di Giffoni'

Hazelnut represents a significant component of the fruit industry in the Lazio region of Italy, but it is struggling with competition on the international market. One approach to restore the competitive ability of the industry is improving quality assessment and developing strong association of the product with the site of production in the perception of the consumer. It is therefore important to define and evaluate qualitative aspects of hazelnut cultivars such as ‘Tonda Gentile Romana’ and ‘Tonda di Giffoni’ in relation to soil and climatic conditions, as well as orchard management practices in the typical areas of cultivation. The following data were collected for both cultivars in five orchards located in the Monti Cimini area (Viterbo), including: chemical and physical soil properties, leaf analysis, nut and seed size, percentage of kernel fill, blanching score, kernel flavor and texture and chemical composition. Multiple years of observations showed that the combination of pedoclimatic conditions and orchard management practices clearly influence nut and seed traits; particularly, higher levels of organic matter and nitrogen in the volcanic soils of the orchards studied correspond to improved kernel/shell ratio and higher taste panel scores. The chemical composition of kernels is also influenced by the cultivation area, with significant differences in quality and quantity of amino acids, carbohydrates and aromatic compounds, which implies the potential for identifying product origin on a chemical basis.